Pulley cover assembly for motorcycle transmission

ABSTRACT

Disclosed herein is a pulley cover assembly for a motorcycle transmission which can securely support a pulley to minimize an shivering phenomenon thereof caused when a load is applied to the rotating pulley, thereby attenuating noise due to the shivering phenomenon and improving a rotational performance of the pulley. Further, the pulley cover assembly can ensure convenient clutch operation through the use of a hydraulic clutch operating mechanism. The clutch operating mechanism includes a hydraulic casing integrally formed at the pulley cover and having a hydraulic oil inlet passage and a hydraulic oil outlet passage, and a piston disposed inside the hydraulic casing while being fixed to an end of the clutch rod of the motorcycle transmission. Such a clutch operating mechanism is adapted to supply hydraulic power into the hydraulic casing to permit the piston to linearly move the clutch rod by a predetermined distance. The pulley cover assembly comprises a pulley supporting means positioned at one side of the pulley opposite to a transmission cover to permit the pulley to be securely supported at both ends thereof by both the pulley supporting means and the transmission cover.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed herein with respect to Korean Patent Application No.10-2004-0045609 filed in the Korean Patent Office on Jun. 18, 2004, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pulley cover assembly for amotorcycle transmission, and more particularly, to a pulley coverassembly for a motorcycle transmission which can permit not only securesupport of a pulley rotatably mounted on an intermediate shaft of themotorcycle transmission to thereby ensure smooth rotating motion of thepulley with an improved rotational performance, but also hydraulicoperation of a clutch operating mechanism to thereby ensure convenientclutch operation.

2. Description of the Related Art

In general, motorcycles perform transmission of rotatory power producedfrom a motorcycle engine via a motorcycle transmission. Then, therotatory power is delivered to a driving pulley 1, which is connected toa driven pulley 2, mounted on a motorcycle's rear wheel, via a belt 3 asshown in FIG. 1, to thereby permit rotation of the rear wheel. Thedriving pulley 1 is located at one side of the motorcycle transmissionso as to freely rotate on an intermediate shaft 4 of the motorcycletransmission. Such a driving pulley 1 is conventionally interposedbetween the motorcycle's front and rear wheels.

A pulley cover assembly 5 is fixedly mounted at one side of themotorcycle transmission, and as shown in FIG. 1, serves to cover andprotect the driving pulley 1 while improving the appearance thereof. Thepulley cover assembly 5 includes a clutch operating mechanism to permitengagement or disengagement of a clutch disc included in the motorcycletransmission.

Referring to FIG. 2 illustrating the interior configuration of theconventional pulley cover assembly 5, the pulley cover assembly 5consists of a pulley cover 5 a to cover and protect the driving pulley1, and the clutch operating mechanism mounted at one side of the pulleycover 5 a.

The driving pulley 1 is engaged at a rotational center portion thereofwith teeth of an output gear 6 of the motorcycle transmission so as torotate simultaneously with the output gear 6. A separation-preventingplate 15 is coupled to both the engaged driving pulley 1 and the outputgear 6 to prevent unintentional separation of the driving pulley 1 fromthe output gear 6. The output gear 6 is supported on the outercircumference of the intermediate shaft 4 via bearings 7 in a rotatablemanner. Consequently, the driving pulley 1 is supported on theintermediate shaft 4 so as to freely rotate about the intermediate shaft4.

The pulley cover Sa defines an interior space suitable to accommodatethe driving pulley 1 and is opened at one side thereof to permit accessto the driving pulley 1. The pulley cover 5 a, covering the drivingpulley 1, is fastened to a transmission cover 8 by means of fasteners.

The clutch operating mechanism includes a case 9 attached to the outerside of the pulley cover 5 a, and a fixed plate 10 and a moving plate 11disposed inside the case 9. The fixed plate 10 is affixed to an innersurface of the case 9 by fixing means, while the moving plate 11,positioned to face the fixed plate 10, is supported by the case 9 so asto freely rotate about the same axis as the intermediate shaft 4.

To the moving plate 11 is fastened one end of a clutch rod 12. The otherend of the clutch rod 12 is inserted through an axial through-borecentrally formed in the intermediate shaft 4 by passing through thepulley cover 5 and comes into contact with a connection rod 13, which isconnected to a clutch disc (not shown) of the motorcycle transmission.

Meanwhile, a ball 14 is interposed between the fixed plate 10 and themoving plate 11. The ball 14 is seated in an inclined circumferentialgroove lib defined at a surface of the moving plate 11. A distal end 11a of the moving plate 11 opposite to the inclined circumferential groove11 b is connected to a clutch lever (not shown), provided at amotorcycle handle, via a wire (not shown).

With such a configuration, when a motorcyclist pulls the clutch lever,the wire, connected between the clutch lever and the moving plate 11, ispulled to rotate the moving plate 11. The rotation of the moving plate11 causes the ball 14 to move toward a shallow side of the inclinedcircumferential groove 11 b to permit the moving plate 11 to move faraway from the fixed plate 10 toward a position as is shown in FIG. 2.Thereby, by movement of the rotating moving plate 11, the clutch rod 12and the connection rod 13 cooperate to drive the clutch disc (not shown)of the motorcycle transmission to implement clutch operation.Conversely, if the motorcyclist releases the clutch lever, theconnection rod 13, the clutch rod 12 and the moving plate 11 aresuccessively returned to their original positions upon operation of anelastic restoration means provided at the clutch disc.

However, with the conventional pulley cover assembly 5 configured asstated above, since one side of the driving pulley 1 is in anunsupported unstable state although the other side of the driving pulley1, which is rotatably mounted on a distal end of the intermediate shaft4 protruding from the motorcycle transmission, is supported by thetransmission cover 8, there is a problem of an shivering phenomenon onthe distal end of the intermediate shaft 4 and on the pulley 1 when adriving load of the motorcycle is applied to the pulley 1. Such anshivering phenomenon induces undue noise, deteriorates rotationalperformance of the pulley 1, and results in wear or degradation ofelements associated with a specific portion of the pulley 1 rotatablysupported on the intermediate shaft 4, reducing the life span of thepulley 1.

Further, the clutch operating mechanism of the conventional pulley coverassembly 5 is inconvenient in use because it must be only manuallydriven through linear movement of the moving plate 11 caused by apulling force of the wire.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide apulley cover assembly for a motorcycle transmission which can permitsecure support of a pulley and minimize an shivering phenomenon possiblycaused by load applied to the pulley upon rotation, thereby attenuatingnoise due to the shivering phenomenon and improving a rotationalperformance of the pulley.

It is another object of the present invention to provide a pulley coverassembly for a motorcycle transmission which can permit hydraulicoperation of a clutch operating mechanism, thereby ensuring easy andconvenient clutch operation.

In accordance with an aspect, the present invention provides a pulleycover assembly for a motorcycle transmission comprising a pulley coverto cover and protect a pulley rotatably supported on a distal end of anintermediate shaft protruding through a transmission cover, and a clutchoperating mechanism provided at one side of the pulley cover to operatea clutch rod of the motorcycle transmission, the pulley cover assemblyfurther comprising a pulley supporting means positioned at an one sideof the pulley opposite to the transmission cover to permit the pulley tobe supported at both sides thereof by both the pulley supporting meansand the transmission cover.

Preferably, the clutch operating mechanism may include a hydrauliccasing integrally formed at the pulley cover and having a hydraulic oilinlet passage and a hydraulic oil outlet passage, and a piston disposedinside the hydraulic casing while being fixed to an end of the clutchrod of the motorcycle transmission, whereby the clutch operatingmechanism supplies hydraulic power into the hydraulic casing to permitthe piston to linearly move the clutch rod by a predetermined distance.

Preferably, the pulley supporting means may include a rotatablesupporting bracket installed between the pulley and the pulley cover andaffixed to a surface of the pulley, and a bearing installed between therotatable supporting bracket and the pulley cover.

Preferably, the pulley supporting means may include an extendedintermediate shaft portion integrally extending from the intermediateshaft of the motorcycle transmission toward the pulley cover to supportthe pulley thereon in a rotatable manner, and a bearing installedbetween the pulley cover and the extended intermediate shaft portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a front view illustrating an installed state of a conventionalpulley cover assembly for a motorcycle transmission;

FIG. 2 is a sectional view of the conventional pulley cover assemblyshown in FIG. 1;

FIG. 3 is a sectional view of a pulley cover assembly for a motorcycletransmission in accordance with a first embodiment of the presentinvention;

FIG. 4 is a sectional view taken along line A-A shown in FIG. 3; and

FIG. 5 is a sectional view of a pulley cover assembly for a motorcycletransmission in accordance with a second embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferred and alternative embodiments of the present invention willbe described in detail with reference to the annexed drawings.

FIG. 3 is a sectional view of a pulley cover assembly for a motorcycletransmission in accordance with a first embodiment of the presentinvention. As shown in FIG. 3, the pulley cover assembly of the presentinvention comprises a pulley cover 22 to cover and protect a pulley 21,a clutch operating mechanism mounted at one side of the pulley cover 22and adapted to operate a clutch rod 23 of the motorcycle transmission,and a pulley supporting means to support one side of the pulley 21,which is supported at the other side thereof by a transmission cover 24.

The pulley 21 serves to receive rotatory power from the motorcycletransmission and deliver the rotatory power to a driven pulley, mountedon a motorcycle's rear wheel, via a belt (see FIG. 1). The pulley 21 isengaged at a rotational center portion thereof with teeth of an outputgear 25 of the motorcycle transmission penetrating through thetransmission cover 24 so as to rotate simultaneously with the outputgear 25. The output gear 25 is rotatably supported on the outercircumference of an intermediate shaft 26 via bearings 27. Consequently,the pulley 21 is supported on the intermediate shaft 26 so as to freelyrotate about the intermediate shaft 26.

The pulley cover 22 defines an interior space suitable to accommodatethe pulley 21 and is opened at one side thereof to permit access to thepulley 21. The pulley cover 22, covering the pulley 21, is fastened tothe transmission cover 24 by means of fasteners. Such an arrangement iseffective to protect a specific portion of the pulley 21, assembled toan associated portion of the motorcycle transmission, from the outsidewhile improving the appearance thereof.

The clutch operating mechanism includes a hydraulic casing 28 integrallyformed at the pulley cover 22 and having a hydraulic oil inlet passage28 a and a hydraulic oil outlet passage 28 b, and a piston 29 disposedinside the casing 28 while being fixed to an end of the clutch rod 23 ofthe motorcycle transmission.

The other end of the clutch rod 23, in the same manner as the prior art,is inserted through an axial through-bore centrally formed in theintermediate shaft 26 by passing through the pulley cover 22 and comesinto contact with a connection rod 30, which is connected to a clutchdisc (not shown) of the motorcycle transmission.

Meanwhile, in the present embodiment, a conventional hydraulic powersupply device is provided to supply hydraulic power into the hydrauliccasing 28. Referring to FIG. 4 shown as a sectional view taken alongline A-A shown in FIG. 3, the hydraulic power supply device is comprisedof a master cylinder 31 to produce hydraulic power through manualoperation of a clutch lever (not shown), an feed pipe 32 to deliver theproduced hydraulic power from the master cylinder 31 to the hydraulicoil inlet passage 28 a of the hydraulic casing 28, and a return pipe 33to return the hydraulic power outlet from the hydraulic oil outletpassage 28 b of the hydraulic casing 28 into the master cylinder 31.Both the feed pipe 32 and the return pipe 33 are installed with checkvalves 34 and 35, respectively, to permit supply of the hydraulic powerin only a direction marked by arrows.

With such a configuration, when a motorcyclist pulls the clutch lever,the hydraulic power, produced by the master cylinder 31, is deliveredinto the hydraulic casing 28 so as to move the piston 29 to a positionas is shown in FIG. 3. Thereby, through cooperation of the clutch rod 23and the connection rod 30, the clutch disc (not shown) of the motorcycletransmission can be operated. Conversely, when the motorcyclist releasesthe clutch lever, the connection rod 30, the clutch rod 23 and thepiston 29 are returned to their original positions upon operation of anelastic restoration means provided at the clutch disc. As a result, thehydraulic power is returned from the hydraulic casing 28 into the mastercylinder 31 via the hydraulic oil outlet passage 28 b.

The pulley supporting means includes a rotatable supporting bracket 36installed between the pulley 21 and the pulley cover 22, and a bearing37 installed between the rotatable supporting bracket 36 and the pulleycover 22. The rotatable supporting bracket 36 has a fixed portion 36 aand a rotatable supporting portion 36 b. The fixed portion 36 a isfastened to the pulley 21 by means of fastening means, such as bolts, soas to prevent separation of the pulley 21.

The pulley cover 22 has a hollow cylindrical supporting portion 22 aprotruding toward the pulley 21, and the bearing 37 of the pulleysupporting means is inserted between the rotatable supporting portion 36b of the rotatable supporting bracket 36 and the cylindrical supportingportion 22 a of the pulley cover 22 so as to support the supportingbracket 36 in a rotatable manner.

With the pulley cover assembly for the motorcycle transmission inaccordance with the first embodiment of the present invention, one sideof the pulley 21 is supported by the transmission cover 24, and theother side of the pulley 21 is supported by the supporting portion 22 aof the pulley cover 22 via both the rotatable supporting bracket 36 andthe bearing 37. This permits the pulley 21 to be securely supported atboth sides thereof.

Thereby, even if any load is applied to the pulley 21 during motorcycledriving, an shivering phenomenon on the pulley 21 can be minimized tothereby permit an attenuated noise and an enhanced rotationalperformance of the pulley 21, and eliminates the risk of wear ordegradation of elements associated with a specific portion of the pulley21 rotatably supported on the intermediate shaft 26 of the motorcycletransmission.

Further, the clutch operating mechanism of the pulley cover assemblyaccording to the present invention permits hydraulic clutch operation byvirtue of the hydraulic casing 28 formed with the hydraulic oil inletand outlet passages 28 a and 28 b as well as the piston 29 disposedinside the hydraulic casing 28. The hydraulic operation can allow easyand convenient clutch operation.

FIG. 5 is a sectional view of a pulley cover assembly for the motorcycletransmission in accordance with a second embodiment of the presentinvention. The present embodiment is different from the first embodimentin the configuration of a pulley support means which is used to supportone side of the pulley 21, which is supported at the other side thereofby the transmission cover 24, and is equal to the first embodiment inconfigurations of the pulley cover 22 which covers and protects thepulley 21 and the clutch operating mechanism which is disposed at oneside of the pulley cover 22 to operate the clutch rod 23 of themotorcycle transmission. Therefore, components identical to those of thefirst embodiment are designated by the same references and theirdetailed description will be omitted.

The pulley supporting means of the second embodiment of the presentinvention includes an extended intermediate shaft portion 41 integrallyextending from the intermediate shaft 26 of the motorcycle transmissiontoward the pulley cover 22 to support the pulley 21 thereon in arotatable manner, and a bearing 42 installed between the pulley cover 22and the extended intermediate shaft portion 41. The bearing 42 isinserted between the outer circumference of the extended intermediateshaft portion 41 and the inner circumference of the cylindricalsupporting portion 22 a of the pulley cover 21 so as to support theextended intermediate shaft portion 41 in a rotatable manner. A fixingplate 43 is coupled to the pulley 21 so as to prevent separation of thepulley 21.

With the pulley cover assembly for the motorcycle transmission accordingto the second embodiment of the present invention, one side of thepulley 21 is supported by the transmission cover 24, and the other sideof the pulley 21 is supported by the supporting portion 22 a of thepulley cover 22 via the bearing 42. This permits the pulley 21 to besecurely supported at both sides thereof.

Thereby, even if any load is applied to the pulley 21 during motorcycledriving, an shivering phenomenon on the pulley 21 can be minimized tothereby permit an attenuated noise and an enhanced rotationalperformance of the pulley 21, and eliminates the risk of wear ordegradation of elements associated with a specific portion of the pulley21 rotatably supported on the extended intermediate shaft portion 41extending from the intermediate shaft 26 of the motorcycle transmission.

As apparent from the above description, the present invention provides apulley cover assembly for a motorcycle transmission capable of securelysupporting both sides of a pulley. Such a pulley cover assembly canminimize an shivering phenomenon possibly caused on the pulley when adriving load of a motorcycle is applied to the pulley, therebyattenuating noise due to the shivering phenomenon, improving arotational performance of the pulley, and minimizing wear or degradationof elements due to the shivering phenomenon so as to extend the lifespan of the pulley. Further, according to the present invention, aclutch operating mechanism of the pulley cover assembly can behydraulically operated, ensuring easy and convenient clutch operation.

Although the preferred embodiment of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A pulley cover assembly for a motorcycle transmission comprising apulley cover to cover and protect a pulley rotatably supported on adistal end of an intermediate shaft protruding through a transmissioncover, and a clutch operating mechanism provided at one side of thepulley cover to operate a clutch rod of the motorcycle transmission, thepulley cover assembly further comprising: a pulley supporting meanspositioned at an one side of the pulley opposite to the transmissioncover to permit the pulley to be supported at both sides thereof by boththe pulley supporting means and the transmission cover.
 2. The assemblyas set forth in claim 1, wherein the clutch operating mechanismincludes: a hydraulic casing integrally formed at the pulley cover andhaving a hydraulic oil inlet passage and a hydraulic oil outlet passage;and a piston disposed inside the hydraulic casing while being fixed toan end of the clutch rod of the motorcycle transmission, whereby theclutch operating mechanism supplies hydraulic power into the hydrauliccasing to permit the piston to linearly move the clutch rod by apredetermined distance.
 3. The assembly as set forth in claim 1, whereinthe pulley supporting means includes: a rotatable supporting bracketinstalled between the pulley and the pulley cover and affixed to a sideof the pulley; and a bearing installed between the rotatable supportingbracket and the pulley cover.
 4. The assembly as set forth in claim 1,wherein the pulley supporting means includes: an extended intermediateshaft portion integrally extending from the intermediate shaft of themotorcycle transmission toward the pulley cover to support the pulleythereon in a rotatable manner; and a bearing installed between thepulley cover and the extended intermediate shaft portion.
 5. A pulleycover assembly for a motorcycle transmission comprising a pulley coverto cover and protect a pulley rotatably supported on a distal end of anintermediate shaft protruding through a transmission cover, and a clutchoperating mechanism provided at one side of the pulley cover to operatea clutch rod of the motorcycle transmission, wherein the clutchoperating mechanism includes: a hydraulic casing integrally formed atthe pulley cover and having a hydraulic oil inlet passage and ahydraulic oil outlet passage; and a piston disposed inside the hydrauliccasing while being fixed to an one end of the clutch rod of themotorcycle transmission, whereby the clutch operating mechanism supplieshydraulic power into the hydraulic casing to permit the piston tolinearly move the clutch rod by a predetermined distance.